While the general topic of stem cell research has vastly complicated (mostly unnecessarily so) political and religious dimensions, an article in Nature throws some light on the main points of contention. Much of the debate seems to centre on opinions about 'when life begins'.
1. Apparently, Islam and Judaism have no problem with embryonic research. According to their tenets, 'life begins 40 days after conception' (I would surely like to know the method, if there is any, which they used to determine this!) and so there's no harm in using a younger than 40 days embryo for extracting stem cells.
2. The stance of Hinduism is interesting, and again reminds me of the general quality of tolerance that is embodied in that religion. According to Hindu philosophy, life does begin at conception. However, according to Swami Tyagananda at MIT, there is no problem in destroying life in an embryonic stage, if it is being done for the greater good. In the Mahabharata, Krishna has no qualms about even resorting to trickery in killing the Kauravas, because it ultimately would lead to a much greater good, and the principle seems to have endured after such a long time. This is probably much better than any other religious belief, except for the fact that in the cloistered precincts of human affairs, 'the greater good' is frequently hard to define. In this case, however, I am happy to note that it is taken to mean curing Alzheimer's and other serious diseases. For once, Swami Tyagananda and the scientists seemed to have reached an agreement.
Scientifically, even the opinion that life begins at conception seems to me to be a fuzzy concept. How do you define the exact moment of conception? Is it during the act of conception? Or when the sperm reaches the ovum? Or when it penetrates the ovum?...We could go on. The problem ironically is, even the seemingly well-defined (and frequently fanatical) beliefs of religion are never ever unambiguous.
3. Predictably, the strongest objections come from Christian sects that condemn the 'killing' of an embryo, even if it is a three day old amorphous clump of cells. While this roughly matches current Vatican thinking, that institution seems to conform more to our idea of a 'human rights group'. The Vatican does not strictly claim that the early embryo is a person- only that 'it deserves respect as a potential human being'. Eventually, the Vatican may even change its opinions, but only in the kind of agonizingly slow process that Galileo's case demonstrated.
Last but not the least, I don't even need to voice my opinions about the sheer stupidity of groups who are arguing against birth control pills because they apparently prevent the embryo from forming and hence stifle life...
At this rate, finally, only the God who many scientists and rationalists don't believe in could possibly save them...and everyone else!!